The team found that a compound called JQ1 was successful as a sperm production inhibitor when used in mice. The formulation also works by reducing sperm mobility.
And though the compound is so far delivered through injection, the team are confident they could soon formulate a pill with the same efficacy.
The discovery could be the answer to an industry search for the male pill, with recent studies suggesting more than 70 per cent of men would be willing to take it were it available.
Furthermore unlike the female pill, which can have side effects such as interfering with hormones, the study suggests JQ1 does not affect testosterone levels at all.
“More good news is that there appear to be no side effects whatsoever,” said Qinglei Li, an assistant professor working on the project. “Once the JQ1 was no longer given to the mice, they were back to their normal reproduction rates, and it did not affect mating behavior or the health of the offspring.”
"This is an exciting step in male contraception," Li added. "A compound with more specificity will be needed before clinical trials can be done for humans. It does not mean a male birth control just yet, but it is a great step forward in that direction."
How it works
The compound targets bromodomain, found in the testis-specific protein known as BRDT (Bromodomain testis-specific protein).
When inhibited BRDT has been found to reduce sperm production and motility. However the targeted delivery mechanism is one of the first to do it without affecting hormone levels.
“Unequivocally, JQ1 is a BET family inhibitor that exerts its contraceptive effect on the male germline during the peak of expression of BRDT,” the research, published in Cell Journal, says.
“We are currently creating and testing the effects of JQ1 derivatives possessing selectivity for BRDT to extend the favourable therapeutic window of BRDT inhibition for male contraception.”